Modern integrated circuits are made up of thousands to millions of active devices such as transistors and passive devices such as capacitors and/or inductances. Technological advances in IC techniques and designs have produced generations of ICs, and each generation has smaller and more complex circuits than the previous generation. These devices are initially isolated from each other, but are later interconnected together through multiple metal layers and via contacts to form functional circuits. As the IC becomes increasingly more complex, the density of active and passive devices in modern integrated circuits is significantly increased, and therefore it is required to decrease the dimension of these devices. Currently, the semiconductor industry has progressed into nanometer technology nodes for higher device density and better electrical performance. However, as device scaling down continues, conventional techniques have not been entirely satisfactory in all respects.